/*
 * ORACLE PROPRIETARY/CONFIDENTIAL. Use is subject to license terms.
 *
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/*
 * Copyright (c) 2009 by Oracle Corporation. All Rights Reserved.
 */

package javax.xml.stream;

import javax.xml.stream.events.*;
import javax.xml.stream.util.XMLEventConsumer;
import javax.xml.namespace.NamespaceContext;

/**
 *
 * This is the top level interface for writing XML documents.
 *
 * Instances of this interface are not required to validate the
 * form of the XML.
 *
 * @version 1.0
 * @author Copyright (c) 2009 by Oracle Corporation. All Rights Reserved.
 * @see XMLEventReader
 * @see javax.xml.stream.events.XMLEvent
 * @see javax.xml.stream.events.Characters
 * @see javax.xml.stream.events.ProcessingInstruction
 * @see javax.xml.stream.events.StartElement
 * @see javax.xml.stream.events.EndElement
 * @since 1.6
 */
public interface XMLEventWriter extends XMLEventConsumer {

    /**
     * Writes any cached events to the underlying output mechanism
     * @throws XMLStreamException
     */
    public void flush() throws XMLStreamException;

    /**
     * Frees any resources associated with this stream
     * @throws XMLStreamException
     */
    public void close() throws XMLStreamException;

    /**
     * Add an event to the output stream
     * Adding a START_ELEMENT will open a new namespace scope that
     * will be closed when the corresponding END_ELEMENT is written.
     * <table border="2" rules="all" cellpadding="4">
     *   <thead>
     *     <tr>
     *       <th align="center" colspan="2">
     *         Required and optional fields for events added to the writer
     *       </th>
     *     </tr>
     *   </thead>
     *   <tbody>
     *     <tr>
     *       <th>Event Type</th>
     *       <th>Required Fields</th>
     *       <th>Optional Fields</th>
     *       <th>Required Behavior</th>
     *     </tr>
     *     <tr>
     *       <td> START_ELEMENT  </td>
     *       <td> QName name </td>
     *       <td> namespaces , attributes </td>
     *       <td> A START_ELEMENT will be written by writing the name,
     *       namespaces, and attributes of the event in XML 1.0 valid
     *       syntax for START_ELEMENTs.
     *       The name is written by looking up the prefix for
     *       the namespace uri.  The writer can be configured to
     *       respect prefixes of QNames.  If the writer is respecting
     *       prefixes it must use the prefix set on the QName.  The
     *       default behavior is to lookup the value for the prefix
     *       on the EventWriter's internal namespace context.
     *       Each attribute (if any)
     *       is written using the behavior specified in the attribute
     *       section of this table.  Each namespace (if any) is written
     *       using the behavior specified in the namespace section of this
     *       table.
     *       </td>
     *     </tr>
     *     <tr>
     *       <td> END_ELEMENT  </td>
     *       <td> Qname name  </td>
     *       <td> None </td>
     *       <td> A well formed END_ELEMENT tag is written.
     *       The name is written by looking up the prefix for
     *       the namespace uri.  The writer can be configured to
     *       respect prefixes of QNames.  If the writer is respecting
     *       prefixes it must use the prefix set on the QName.  The
     *       default behavior is to lookup the value for the prefix
     *       on the EventWriter's internal namespace context.
     *       If the END_ELEMENT name does not match the START_ELEMENT
     *       name an XMLStreamException is thrown.
     *       </td>
     *     </tr>
     *     <tr>
     *       <td> ATTRIBUTE  </td>
     *       <td> QName name , String value </td>
     *       <td> QName type </td>
     *       <td> An attribute is written using the same algorithm
     *            to find the lexical form as used in START_ELEMENT.
     *            The default is to use double quotes to wrap attribute
     *            values and to escape any double quotes found in the
     *            value.  The type value is ignored.
     *       </td>
     *     </tr>
     *     <tr>
     *       <td> NAMESPACE  </td>
     *       <td> String prefix, String namespaceURI,
     *            boolean isDefaultNamespaceDeclaration
     *      </td>
     *       <td> None  </td>
     *       <td> A namespace declaration is written.  If the
     *            namespace is a default namespace declaration
     *            (isDefault is true) then xmlns="$namespaceURI"
     *            is written and the prefix is optional.  If
     *            isDefault is false, the prefix must be declared
     *            and the writer must prepend xmlns to the prefix
     *            and write out a standard prefix declaration.
     *      </td>
     *     </tr>
     *     <tr>
     *       <td> PROCESSING_INSTRUCTION  </td>
     *       <td>   None</td>
     *       <td>   String target, String data</td>
     *       <td>   The data does not need to be present and may be
     *              null.  Target is required and many not be null.
     *              The writer
     *              will write data section
     *              directly after the target,
     *              enclosed in appropriate XML 1.0 syntax
     *      </td>
     *     </tr>
     *     <tr>
     *       <td> COMMENT  </td>
     *       <td> None  </td>
     *       <td> String comment  </td>
     *       <td> If the comment is present (not null) it is written, otherwise an
     *            an empty comment is written
     *      </td>
     *     </tr>
     *     <tr>
     *       <td> START_DOCUMENT  </td>
     *       <td> None  </td>
     *       <td> String encoding , boolean standalone, String version  </td>
     *       <td> A START_DOCUMENT event is not required to be written to the
     *             stream.  If present the attributes are written inside
     *             the appropriate XML declaration syntax
     *      </td>
     *     </tr>
     *     <tr>
     *       <td> END_DOCUMENT  </td>
     *       <td> None </td>
     *       <td> None  </td>
     *       <td> Nothing is written to the output  </td>
     *     </tr>
     *     <tr>
     *       <td> DTD  </td>
     *       <td> String DocumentTypeDefinition  </td>
     *       <td> None  </td>
     *       <td> The DocumentTypeDefinition is written to the output  </td>
     *     </tr>
     *   </tbody>
     * </table>
     * @param event the event to be added
     * @throws XMLStreamException
     */
    public void add(XMLEvent event) throws XMLStreamException;

    /**
     * Adds an entire stream to an output stream,
     * calls next() on the inputStream argument until hasNext() returns false
     * This should be treated as a convenience method that will
     * perform the following loop over all the events in an
     * event reader and call add on each event.
     *
     * @param reader the event stream to add to the output
     * @throws XMLStreamException
     */

    public void add(XMLEventReader reader) throws XMLStreamException;

    /**
     * Gets the prefix the uri is bound to
     * @param uri the uri to look up
     * @throws XMLStreamException
     */
    public String getPrefix(String uri) throws XMLStreamException;

    /**
     * Sets the prefix the uri is bound to.  This prefix is bound
     * in the scope of the current START_ELEMENT / END_ELEMENT pair.
     * If this method is called before a START_ELEMENT has been written
     * the prefix is bound in the root scope.
     * @param prefix the prefix to bind to the uri
     * @param uri the uri to bind to the prefix
     * @throws XMLStreamException
     */
    public void setPrefix(String prefix, String uri) throws XMLStreamException;

    /**
     * Binds a URI to the default namespace
     * This URI is bound
     * in the scope of the current START_ELEMENT / END_ELEMENT pair.
     * If this method is called before a START_ELEMENT has been written
     * the uri is bound in the root scope.
     * @param uri the uri to bind to the default namespace
     * @throws XMLStreamException
     */
    public void setDefaultNamespace(String uri) throws XMLStreamException;

    /**
     * Sets the current namespace context for prefix and uri bindings.
     * This context becomes the root namespace context for writing and
     * will replace the current root namespace context.  Subsequent calls
     * to setPrefix and setDefaultNamespace will bind namespaces using
     * the context passed to the method as the root context for resolving
     * namespaces.
     * @param context the namespace context to use for this writer
     * @throws XMLStreamException
     */
    public void setNamespaceContext(NamespaceContext context) throws XMLStreamException;

    /**
     * Returns the current namespace context.
     * @return the current namespace context
     */
    public NamespaceContext getNamespaceContext();

}
